【作者】 黎志银；

【导师】 谢宝贵；

【作者基本信息】 福建农林大学 ， 微生物学， 2010， 硕士

【摘要】 食用菌子实体中的重金属和农药残留等危害物质超标问题是食用菌产品质量安全的主要问题,也是控制食用菌产品质量安全的关键问题。本文通过在栽培料添加Hg、Cd、Pb、As四种不同浓度的重金属盐类,研究香菇等7种食用菌栽培基质中重金属含量的变化规律,以及子实体对四种重金属的吸收规律,建立7种食用菌对四种重金属积累效应的数学模型。结果表明:四种重金属在食用菌栽培料中不易降解,栽培料经高温灭菌后不影响重金属的含量,而在子实体采收后重金属的含量有增加的趋势;食用菌子实体内重金属含量与栽培基质中重金属添加量存在显著相关性,添加量越多,吸收值越大,但食用菌对不同重金属的吸收能力有所差别,7种食用菌对4种重金属的吸收能力大小为顺序为Hg>Cd >Pb>As;通过建立子实体对重金属的积累方程y=c/(1+ea-bx),计算出各种食用菌的重金属背景值含量及可能的最大积累量。以国标对食用菌产品安全限量值为依据,利用积累方程的反函数预测出食用菌栽培料中的重金属安全限值,为从源头上控制重金属污染提供科学依据。本文还选取了敌敌畏等9种农药在香菇等6种食用菌上进行残留试验。研究了农药对食用菌生长的影响、农药在食用菌菌丝和子实体生长过程中的降解规律以及不同施药方法在子实体中的最终残留。结果表明:这9种农药对食用菌菌丝和子实体生长都有不同程度的影响,其中食用菌菌丝在0.1%敌敌畏和0.1%毒死蜱培养基中都不生长,0.1%甲基托布津对猴头菇菌丝的抑制率为100%,菊酯类农药对菌丝生长影响较小。出菇期间喷施敌敌畏会导致秀珍菇、茶树菇不出菇,喷施毒死蜱也会导致多数子实体生长畸形。在研究农药降解规律试验中,农药以拌料方式使用降解比较彻底,在高温灭菌时一些农药就已经大部分降解,其中敌敌畏几乎100%降解,甲基托布津基本上降解为多菌灵,菌丝生长过程中也会降解大部分农药。出菇期间喷洒农药,由于子实体生长期短,农药降解较不彻底,比如香菇子实体上农药降解最快,半衰期最大的农药为联苯菊酯和百菌清,都是1.65d,最小的甲基托布津仅为0.25d。农药在食用菌中的残留情况,拌料方式施用不易导致子实体残留超标,只有毒死蜱和甲氰菊酯的部分处理残留超出标准。出菇时喷施农药比较容易导致子实体残留超标,比如在香菇子实体残留试验中,9种农药在以下喷施方法中都不会导致子实体残留量超标:敌敌畏开袋时喷施150mL/667m2剂量,毒死蜱在刚开袋时喷施112.5g/667m2剂量,联苯菊酯子实体长出后仍可以施用15mL/667m2剂量,甲氰菊酯在子实体未长出时喷施45mL/667m2剂量,氯氰菊酯在子实体长出后施用剂量35mL/667m2,溴氰菊酯在子实体长出后施用剂量80mL/667m2,多菌灵、甲基托布津、百菌清在开袋时施药,最高使用剂量分别为300g/667m2、215.5g/667m2、405g/667m2。本文还介绍了另外5种食用菌的农药残留试验结果。更多还原

【Abstract】 The problem of excessive heavy metals and pesticide residues in the edible fungi fruit body is not only the main problem in the quality and safety assure of edible fungi production, but also the key measure to control the quality and safety of edible fungi.The research study the heavy metals variation of cultivation substract in different periods, the heavy metals absorption regulation of edible fungi and the build-up effect of the absorption regulation using mathematical model via adding different concentration of heavy metals to the cultivation substract. The results showed that the existence of heavy metals in the cultivation material was quite steady, high-temperature sterilization of the cultivation had almost no effect on heavy metals, the heavy metals content in the cultivation substract increased after fruit body collection, and the heavy metal abortion increased as the heavy metal content we added increased. The absorption capacity was different between different edible fungi and heavy metals. The accumulation ability of the four heavy metals was as follows: Hg> Cd> Pb> As; the heavy metals content within the edible fungi fruit body was significantly relative with the heavy metal addition to the culture media. The background value and the possible maximum accumulation of all kinds of edible fungis were calculated through the accumulation equation: y = c / (1 + ea-bx). According to the international standard of the safety limited value on the edible fungi products security, we predict the heavy metal’s safety limited value in the edible fungi cultivated substract by using the inverse function of accumulation equation to control the heavy metal pollution.In the article, 9 kinds of pesticides such as dichlorvos were selected to carry on the residues experiment on 6 kinds of edible fungi. The impact of pesticides on the stage of growth, the degradation law of pesticides on the growth process of mycelium and fruiting body and the final residue in fruiting body because of different application methods were separately studied. Then results showed that 9 pesticides’application can have different effects on mycelium and fruit body, (I) all strains no growth at 0.1% dichlorvos and 0.1% chlorpyrifos; (II)100% inhibition of the mycelium of Hericium erinaceus at 0.1% thiophanate methyl, but pyrethroid pesticide no significant impact; (III) Pleurotus ostreatus and agrocybechaxinggu no fruiting if spraying dichlorvos at fruiting stage and most of abnormal fruiting body if spraying chlorpyrifos. After pesticides added to the cultivating materials, 100% of dichlorvos can be all degraded, thiophanate-methy into deltamethrin, chlorothalonil almost all over. What’s more, pesticides can be degraded at the growth of mycelium, almost in fruit body no or few residue, but only chlorpyrifos and fenpropathrin out of standard. Then, after pesticides’application, results also showed lentinulaedodes had the fastest degradation rate. bifenthrin or chlorothalonil with the largest half-time all was 1.65d and at the same time thiophanate-methyl with the smallest was 0.25d. During the the final experiment about residue in lentinulaedodes, spraying 150mL/667m2 dose of dichlorvos when bags were opened, spraying 112.5g/667m2 dose of Chlorpyrifos when bags were opened,spraying pesticides after fruiting, Pesticide residues were quite low by using bifenthrin. spraying 45mL/667m2 dose of fenpropathrin before friuting, Cypermethrin could not surpass 35mL/667m2 after friuting, spraying 112.5g/667m2 dose of Chlorpyrifos after fruiting. Carbendazim, Thiophanate methyl and chlorothalonil can only be sprayed when the bags were opened,with maxium dose reaching 300g/667m2, 215.5g/667m2, 405g/667m2 respectively, Will not lead to fruiting body residues exceeding. In this article,other five kinds of edible fungi also get different results.更多还原